Vibration exposure and symptoms in postal carriers using motorbikes.

An investigation was made on vibration exposure among postal carriers using motorbikes (mainly letter carriers) and vibration symptom manifestations as a means to obtain information on hand-arm vibration exposure limits. The first report deals with the correlation of vibration and cold exposure with white finger symptoms. The group in which daily vibration exposure was greatest, for which the 4-hour equivalent value of the frequency weighted vibration acceleration was estimated to be above 2 m/s2, showed a greater incidence of white finger than other groups, and the changes synchronized with the timing of motorbike antivibration measures. This group, however, also displayed evidence of varying degrees of cold-exposure white finger. The vibration exposure limit was considered to be over 2 m/s2 as the 4-hour equivalent value of the frequency weighted vibration acceleration.